Event Location by Triangular Interpolation for Temporal Decomposition of Speech

Abstract

For low-bit-rate coding and synthesis the evolution of spectral parameters is a source of redundancy to be considered. A triangular interpolation spectral measure (TRISM) is proposed as the basis for an open-loop event location criterion for low-delay temporal decomposition (TD). TRISM comes as an improvement in linear interpolation error measurement over the spectral transition measure (STM). While STM is heuristic and presupposes asymmetric event functions, TRISM is a minimum square interpolation error based on symmetric functions. Minimun TRISM (MINTRISM) TD interpolates up to 13 frames between adjacent events at a mean event rate of 15 Hz and interpolation error level equivalent to that of standard low-bit-rate speech coders. The MINTRISM criterion is also a more stable solution to the location of events and determination of their number than previous global and local TD methods.